Various forms of weight supporting devices designed for use in developing upper arm and shoulder portions of the user have been heretofore designed. However, these previously known exercising devices have not been primarily designed for use in developing the above-mentioned "forearm blow" and many previously designed weight supporting devices of a similar nature have not been readily adaptable for use by persons of young age and adult age requiring light- and heavy-weighting, respectively.
Examples of various forms of previously patented weight supporting structures are disclosed in U.S. Pat. Nos. 348,379, 1,729,209, 2,482,589, 2,504,880 and 3,180,641.